Luminescence method for the study of Nd3+ ions diffusion in AgBr crystals

This study of diffusion of Nd in AgBr is motivated by our interest in the p reparation of Nd-doped AgBr crystals that show lasing effects in the near a nd midinfrared. The doping can be done in several ways. We propose that mon itoring the infrared luminescence along the direction of diffusion of activ ator ions in crystals of AgBr is a sensitive and minimally invasive method of determining the diffusion coefficient, the diffusion enthalpy, and the t emperature dependence of these parameters for ions of interest. We have use d this technique to study the diffusion of Nd3+ in AgBr crystals. To establ ish the concentration range in which the luminescence method is useful, the dependence of the luminescence kinetics on the Nd-ion concentration was in vestigated. The temperature dependence of the diffusion coefficient (D-0 = 1.2 x 10(-5) cm(2)/s at room temperature), and the diffusion enthalpy (H = 0.51 eV) were determined. We found that high values of the diffusion coeffi cient and low values of the diffusion enthalpy facilitate preparation of hi gh optical quality Nd-doped AgBr crystals. Such crystals are candidates for lasing action. (C) 1999 American Institute of Physics. [S0021-8979(99)0720 4-7].